Facebook says it will begin manually reviewing advertisements that target certain groups and address politics, religion, ethnicity and social issues.

The company has informed some advertisers about the new “human review” requirement, warning them that it might cause delays before their ads can appear on the social media platform.

Facebook has had to apologize amid recent revelations of rampant abuse of its automated advertising process to broadcast false news or promote divisive and hateful messages, such as ads aimed at people who’ve expressed anti-Semitic views. The company is also under increasing congressional scrutiny after revealing that ads linked to a Russian internet agency were seen by an estimated 10 million people before and after the 2016 election.

Axios first reported on the written notice to advertisers. Facebook confirmed it Saturday.